JPH0230756A - Reactive ion plating device - Google Patents

Abstract

PURPOSE:To make the quality of a film stable and uniform by detecting discharge spark at the time of ion plating as an indicator of the balance between the amt. of a reactive gas introduced into a vacuum vessel and the amt. of vapor generated from an evaporating source and by feeding back the detected value so as to regulate the flow rate of the reactive gas. CONSTITUTION:This reactive ion plating device is composed essentially of a vacuum vessel 1, a part 7 for introducing a reactive gas into the vessel 1, a crucible 4 holding starting material 3 to be evaporated, a heater 6 for heating the crucible 4 and an ionizer for ionizing vapor of the starting material and the reactive gas. Discharge spark received by a spark receiving part 8 is spectrally analyzed in a spectral analyzing part 9 and the resulting signals are processed to calculate the flow rate of the reactive gas in a computing part 10. The flow rate of the reactive gas is regulated by a controller 11 according to the calculated result.

Description

[Detailed description of the invention] (Industrial application field) In this invention, a substrate is coated with a compound, for example, TiN.

Regarding a reactive ion plating apparatus for forming ceramic coatings such as TiC and CrN, the present invention attempts to propose an apparatus capable of forming coatings with stable characteristics.

(Prior Art) A method has been developed to improve wear resistance, corrosion resistance, and decorativeness by forming a coating of ceramic or the like on the surface of a metal member by ion plating.

However, the film properties of these films cannot be said to be stable, and variations from batch to batch, variation depending on the film forming position, and variation over time are often observed.

One of the reasons for this is that the melting state of the evaporated raw material in the crucible changes over time, and it is difficult to control, so the amount of vapor changes over time due to changes in the melting state, and the raw material One example is that the spatial distribution of vapor changes. As a result, it goes without saying that the deposition rate is 1,
The quality of the film also changes over time and position.

In order to solve such problems, Japanese Patent Application Laid-Open No. 60-2137
In Publication No. 7, Special Publication No. 11n Sho 60-21378, and Japanese Unexamined Patent Publication No. Sho 60-21379, a shutter is provided in the guide path through which the vapor of the evaporation material reaches the surface of the material to be evaporated, and the opening degree of this shutter is controlled. Techniques are disclosed for controlling the steam flow rate and the uniformity of its distribution by adjusting it.

(Problems to be Solved by the Invention) However, although the above-mentioned techniques are effective when the vapor flow is in the viscous flow region, the reactive ion plating method is effective in the case where the vapor flow is in the viscous flow region, but the reactive ion plating method is effective in the case where the vapor flow is in the viscous flow region. When used for this purpose, it was difficult to make the vapor flow distribution uniform by adjusting the opening degree of the shack.

This invention advantageously solves the above problems and achieves
The purpose of the present invention is to propose a reactive ion plating device in which the characteristics of the film subjected to IA are stable both temporally and spatially.

(Means for Solving the Problem) The inventors have studied a reactive ion plating device that can stably form a film with little temporal or spatial variation in the characteristics of the film to be formed. As a result of repeated studies, we found that many of the film properties are determined by the balance between the vapor stars generated from the evaporation source and the reactant gas introduced into the vacuum chamber, and the relationship between this vapor and the reactant gas flow rate. We have found that the balance can be indicated by the color of discharge light in the ionized space between the evaporation source and the substrate during ion plating.

Therefore, if there is a change in the melting state of the evaporated raw material, the color of the discharge light in the ionized space will change, so the amount of vapor or the flow rate of the reaction gas can be controlled accordingly. Since the control of reactive gas meteors is more responsive and controllable, the inventors detected the color of discharge light and its distribution in the ionized space during ion plating, and detected the color and distribution of the discharge light in the ionized space during ion plating. This led to the development of the reactive ion plating apparatus of the present invention, which stabilizes and homogenizes the ion quality obtained by the ion plating method by feeding back the flow rate.

That is, the present invention includes a reaction gas introduction section for introducing a reaction gas into a vacuum container into which a substrate can be carried in and taken out, a crucible for holding an evaporation raw material, and a heating device ξ for evaporating the evaporation raw material in the crucible. , a reactive ion plating apparatus having an ionization device that ionizes raw material vapor and a reaction gas, and a discharge light receiving section that receives discharge light from an ionized space generated in a vacuum container; A spectroscopic section that spectrally spectra discharge light, a calculation section that processes the signal from this spectrometer to calculate the flow rate of the reaction gas to be introduced into the vacuum container, and a control that adjusts the flow rate of the reaction gas based on the result calculated by this calculation section. This is a reactive ion plating apparatus characterized by comprising a film formation stabilizing device comprising:

FIG. 1 shows an example of the configuration of a reactive ion plating apparatus according to the present invention. In the figure, 1 is a vacuum container, 2 is a substrate,
3 is an evaporation source, 4 is a crucible, 5 is a plasma electron gun, 6 is a focusing coil, 7 is a reaction gas introduction tube, 8 is a discharge light receiver,
9 is a spectroscopic section, 10 is a calculation section, and 11 is a control section.

The vacuum container 1 is heated by a vacuum pump (not shown) at 10-
' Vacuum pumped down to torr level. The crucible 4 in this vacuum container 1 holds the evaporation raw material 3. Ar gas is supplied to the plasma electron gun 5, and electric power is supplied from a power supply (not shown) to generate a plasma electron beam with a low voltage of about 60 kW and a large current. The evaporation raw material 3 is evaporated by this electron beam, and a part of the raw material vapor is also ionized. Then, the reaction gas introduced from the reaction gas introduction pipe 7 and these raw material vapors and ions react on the substrate 2, which can be carried in and out, to form a film as a compound. Note that the focusing coil 6 is connected to a DC power source (not shown) and generates a magnetic field to control the focusing property of the plasma electron beam.

The discharge light receiver 8 receives discharge light from the ionized space during ion plating. This is mainly composed of an optical system, and guides the received incident light to the spectroscopic section 9. The received discharge light is separated by a spectrometer 9 and converted into an electrical signal. This spectroscopic section 9 spectrally spectra discharge light using a prism or a diffraction grating, and then converts it into an electric signal using a phototube. The calculation section 10 processes the signal obtained from the spectroscopic section 9 and performs calculations to determine the flow rate of the reaction gas to be introduced into the vacuum vessel 1 based on experimentally obtained data. Based on the reactive gas meteor determined by the calculation unit 10, the control unit 11 controls the flow rate of the reactive gas.

The calculation for determining the reaction gas flow rate in the calculation unit 10 will be specifically described below.

Using Ti as the evaporation raw material and N2 as the reaction gas, ion plating was performed by changing the Ti vapor amount and N2 flow rate as shown in Table 1, and 2 μl of TiN was coated.

The atomic ratio Ti/N, Vickers hardness 11v (kg/mm''), and color of the TiN film formed are also listed in Table 1.

Table FIG. 2 shows the spectrum of discharge light during this ion plating. The test numbers in the figure correspond to the numbers in Table 1.

As is clear from Table 1 and FIG. 2, as the N2 flow during ion plating increases, Ti/N decreases and the color changes to gold. At this time, in the spectrum of the discharge light, the relative intensity in the low wavelength region (300 to 400 nm) decreases (■ to ■). Conversely, as the Ti evaporation amount increases, Ti/N increases, and the color changes from gold to silvery white (■ to ■).

At this time, the relative intensity in the low wavelength region (300 to 400 nm) increases. Furthermore, whether it is a change in the amount of Ti evaporation or a change in the flow rate of the reactant gas (N2),
400 nm) and Ti/N uniquely correspond,
Ti/N increases as its relative strength increases °ζ
There is. In other words, the relative intensity in the low wavelength region, for example, the wavelength 350
This can be obtained by constantly monitoring the relative intensity of the evaporated raw material and controlling the flow rate of the reactant gas in response to changes in the relative intensity due to changes in the amount of vapor due to changes in the melting state of the evaporated raw material. Changes in the film quality of the compound film can be suppressed. The calculation unit 1 determines the reaction gas flow rate in this way.
Perform at 0.

(Function) In the reactive ion plating apparatus according to the present invention, if the melting state of the evaporated raw material changes during ion plating and, for example, the amount of vapor decreases, the discharge light in the ionization space will change if there is an excess of reactive gas meteors. It exhibits a discharge light color corresponding to .

For example, if the evaporation raw material is Cr and the reaction gas is N2, Cr
As the amount of vapor decreases, the color of the discharge light changes from blue-green to yellow-orange. This change in the color of the discharge light is detected by the light receiving section, and the light is separated by the spectrometer to convert the change in the color of the discharge light into an electrical signal. Based on this electrical signal and experimentally obtained data, the calculation section calculates the ratio between the steam amount and the reaction gas flow rate, calculates the appropriate amount of reaction gas flow rate to be introduced, and transmits this signal to the control section. In this case, the reaction gas flow rate is reduced. In this way, even if the amount of vapor of the evaporation raw material or the flow rate of the reaction gas changes, a constant film quality can always be obtained.

FIG. 3 shows another embodiment of the invention. In the figure, the ionization space is divided into two regions, and a film-forming stabilizing device consisting of a discharge light receiving section, a spectroscopic section, a calculation section, and a control section is arranged for each of these two regions. The number of divisions of the ionized space and the number of corresponding deposition stabilization devices are not limited at all.

The numbers in the figure are the same as those in Figure 1, and 12
13 is a reaction gas introduction tube, 13 is a discharge light receiving section, 14 is a spectroscopic section, 15 is a calculation section, and 16 is a control section.

Now, when the melting state of the evaporated raw material 3 changes and therefore the spatial distribution of the amount of vapor changes, the spatial distribution of the discharge light color in the ionized space changes accordingly. For example, if the amount of vapor evaporated from the crucible 4 in the vacuum container increases toward the left in FIG. 3 and decreases toward the right, the discharge light at the left of the ionization space will exhibit a color corresponding to excessive evaporation. On the contrary, the discharge light on the right side of the ionization space exhibits a color corresponding to an excess of reactive gas. These are detected by the discharge light receivers provided on the left and right parts, respectively, and the flow rate of the reaction gas is controlled in the same manner as described above, in this case, the flow rate of the reaction gas supplied from the reaction gas introduction pipe 7 is reduced, On the other hand, a constant film quality is obtained by increasing the amount of reaction gas supplied from the reaction gas introduction pipe 12. Moreover, if the gas discharge ports of the reaction gas introduction tube are distributed in the width or length direction of the substrate, and the supply amount can be controlled independently, a more homogeneous film can be formed.

In this way, temporal and spatial variations in the quality of the film formed on the substrate 2, which can be carried in and carried out, are reduced.

Although the above explanation has focused on an ion plating apparatus using the CD method, the present invention is not limited to the HCD method, and can also be applied to a high frequency excitation method, an activation reaction thin deposition method, an arc discharge method, and the like.

(Example) Example 1 Using Ti as the medical raw material and acetylene as the reaction gas using the reactive ion plating apparatus shown in Fig. 1, a plate with a thickness of 1 mm was prepared.
A film of 1077111 TiC was formed on a steel plate. Table 2 shows the ion plating conditions at this time. After the steel plates are brought in, they are coated stationary and then taken out.

Table 2 After that, the hardness of the TiC coating was measured, and the average was 11v = 30 at micro Vickers hardness (load 30og).
Elemental analysis in the depth direction from the primary coating surface was measured using IHMA.The results are shown in Figure 4.As is clear from the figure, the Ti/C atomic ratio is , which was almost constant in the depth direction.

This is because the film formation state is stable and the film quality is always the same.
Indicates that a film has been formed.

For comparison, a discharge light receiving section 8, a spectroscopic section 9, a calculation section 10,
A TiC film was coated on 10//11 under the same conditions as described above without operating the film-forming stabilizing device consisting of the control unit 11. Thereafter, elemental analysis was performed in the depth direction from the surface of the TiC film. The results are shown in FIG. As is clear from the figure, changes were observed in the element concentrations of Ti and C in the depth direction. In other words, a softening phase with a hardness ratio is formed, and the average hardness is 11.
v = 2000 kg/mm'', which was a low hardness compared to the example in which the film-forming stabilization device was operated.

Example 2 Ion plating of a TiN film was performed on a cold rolled stainless steel strip using a reactive ion plating apparatus shown in FIG. 3 using Ti as the evaporation raw material and N2 as the reaction gas. The cold-rolled stainless steel strip was coated with TiN while being continuously moved in a direction perpendicular to the plane of the paper in a conveyance system (not shown). Table 3 shows the ion plating conditions at this time.

Table 3 Coating was carried out for 3 hours using this equipment, and 180 m” of TiN
A coated cold-rolled steel strip was produced. The chromaticity of the appearance of the TiN coating on the obtained cold-rolled steel strip was measured using the JIS Z 8701 method, and found that x = 0.381 a, = 0.005 y =
0.390 σ = 0.006 (n = 150), which was golden in color and had extremely small variations. In other words, the film quality was stable.

On the other hand, for comparison, the discharge light receiving section 8.13 and the spectroscopic section 9.1
4. Perform TiN coating under the same conditions as described above without operating the calculation unit 10.15 and control unit 11.16, and
When the chromaticity of the film appearance was measured, x = 0.365
σ, = 0.02y = 0.370 σ2y = 0.03 (n = 150), and the variation was large compared to the example. This simply means that the film quality was unstable.

(Effects of the Invention) By using the reactive ion plating apparatus of the present invention, it is possible to obtain an extremely stable compound film with little spatial or temporal variation.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of a reactive ion plating apparatus showing one example of the present invention, FIG. 2 is a graph showing the spectrum of discharge light, and FIG. 3 is a reaction diagram showing another example of the present invention. FIG. 4 is a graph showing the change in element concentration in the depth direction by IHMA of a TiC film obtained using the ion plating device of the present invention. FIG. 2 is a graph showing changes in element concentration in the depth direction due to the thickness of a TiC film obtained using an ion plating device. 1... Vacuum container 2... Substrate 3... Evaporation raw material 4... Crucible 5... Plasma electron gun 6... Focusing coil 7.12... Reaction gas introduction tube 8.13...・Discharge light receiving section 9.14...Spectroscopic section 1
0, 15...Arithmetic unit 11.16...Control unit Fig. 1 Fig. 2 4-1--Rotsubo e-1--Light frame 9 for discharging--Ima-Ku-to- ---7ψ-' m-

Claims (1)

[Claims] 1. A reaction gas introduction part for introducing a reaction gas into a vacuum container into which a substrate can be carried in and out, a crucible for holding an evaporation raw material, and a heating device for evaporating the evaporation raw material in the crucible. , a reactive ion plating apparatus having an ionization device that ionizes raw material vapor and a reaction gas, and a discharge light receiving section that receives discharge light of an ionized space generated in a vacuum container; a spectroscopy section that spectrally spectra the discharge light generated by the spectrometer, a calculation section that processes the signal from the spectrometer to calculate the flow rate of the reaction gas to be introduced into the vacuum vessel, and an adjustment of the flow rate of the reaction gas based on the results calculated by the calculation section. A reactive ion plating apparatus characterized by comprising a film formation stabilizing device comprising a control section.